<!DOCTYPE html>
<html lang="en">
  <head>
    <style>
      body {
        background: url("a.jpg") center center no-repeat;
        background-size: 1440px 880px;
      }
      .login-box {
        position: relative;
        width: 200px;
        height: 200px;
        overflow: hidden;
        /* background-color: white; */
        /* filter: brightness(200%); */
      }
      .login-box::before {
        content: "";
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        width: 100%;
        height: 100%;
        background-color: rgb(3, 25, 47);
        /* background-color: rgba(3, 25, 47, 0.8); */
        filter: blur(20px);
        /* filter: blur(20px) contrast(0.5) opacity(0.5); */
        z-index: -1;
      }
    </style>
  </head>

  <body>
    <div class="login-box">111</div>
  </body>
</html>
